On the 29th birthday of the world wide web, its inventor, Sir Tim Berners-Lee, has sounded a fresh warning about threats to the web as a force for good, adding his voice to growing concerns about big tech’s impact on competition and society.

The web’s creator argues that the “powerful weight of a few dominant” tech platforms is having a deleterious impact by concentrating power in the hands of gatekeepers that gain “control over which ideas and opinions are seen and shared”.

His suggested fix is socially minded regulation, so he’s also lending his clout to calls for big tech to be ruled.

“These dominant platforms are able to lock in their position by creating barriers for competitors,” Berners-Lee writes in an open letter published today on the Web Foundation’s website. “They acquire startup challengers, buy up new innovations and hire the industry’s top talent. Add to this the competitive advantage that their user data gives them and we can expect the next 20 years to be far less innovative than the last.”

The concentration of power in the hands of a few mega platforms is also the source of the current fake news crisis, in Berners-Lee’s view, because he says platform power has made it possible for people to “weaponise the web at scale” — echoing comments made by the UK prime minister last year when she called out Russia for planting fakes online to try to disrupt elections.

“In recent years, we’ve seen conspiracy theories trend on social media platforms, fake Twitter and Facebook accounts stoke social tensions, external actors interfere in elections, and criminals steal troves of personal data,” he writes, pointing out that the current response of lawmakers has been to look “to the platforms themselves for answers” — which he argues is neither fair nor likely to be effective.

In the EU, for example, the threat of future regulation is being used to encourage social media companies to sign up to a voluntary code of conduct aimed at speeding up takedowns of various types of illegal content, including terrorist propaganda. Though the Commission is also seeking to drive action against a much broader set of online content issues — such as hate speech, commercial scams and even copyrighted material.

Some EU member states have gone further too. Germany now has a law with big fines for social media platforms that fail to comply with hate speech takedown requirements, for example, while in the UK ministers are toying with new rules, such as placing limits on screen time for children and teens.

Both the Commission and some EU member states have been pushing for increased automation of content moderation online. In the UK last month, ministers unveiled an extremism blocking tool which the government had paid a local AI company to develop, with the Home Secretary warning she had not ruled out forcing companies to use it.

Meanwhile, in the US, Facebook has faced huge pressure in recent years as awareness has grown of how extensively its platform is used to spread false information, including during the 2016 presidential election.

The company has announced a series of measures aimed at combating the spread of fake news generally, and reducing the risk of election disinformation specifically — as well as a major recent change to its news feed algorithm ostensibly to encourage users towards having more positive interactions on its platform.

But Berners-Lee argues that letting commercial entities pull levers to try to fix such a wide-ranging problem is a bad idea — arguing that any fixes companies come up with will inexorably be restrained by their profit-maximizing context and also that they amount to another unilateral impact on users.

A better solution, in his view, is not to let tech platform giants self-regulate but to create a framework for ruling them that factors in “social objectives”.

A year ago Berners-Lee also warned about the same core threats to the web. Though he was less coherent in his thinking then that regulation could be the solution — instead flagging up a variety of initiatives aimed at trying to combat threats such as the systematic background harvesting of personal data. So he seems to be shifting towards the need for a move overarching framework to control the tech that’s being used to control us.

“Companies are aware of the problems and are making efforts to fix them — with each change they make affecting millions of people,” he writes now. “The responsibility — andsometimes burden — of making these decisions falls on companies that have been built to maximise profit more than to maximise social good. A legal or regulatory framework that accounts for social objectives may help ease those tensions.”

Berners-Lee’s letter also emphasizes the need for diversity of thought in shaping any web regulations to ensure rules don’t get skewed towards a certain interest or group. And he makes a strong call for investments to help close the global digital divide.

“The future of the web isn’t just about those of us who are online today, but also those yet to connect,” he warns. “Today’s powerful digital economy calls for strong standards that balance the interests of both companies and online citizens. This means thinking about how we align the incentives of the tech sector with those of users and society at large, and consulting a diverse cross-section of society in the process.”

Another specific call he makes is for fresh thinking about Internet business models, arguing that online advertising should not be accepted as the only possible route for sustaining web platforms. “We need to be a little more creative,” he argues.

“While the problems facing the web are complex and large, I think we should see them as bugs: problems with existing code and software systems that have been created by people — and can be fixed by people. Create a new set of incentives and changes in the code will follow. We can design a web that creates a constructive and supportive environment,” he adds.

“Today, I want to challenge us all to have greater ambitions for the web. I want the web to reflect our hopes and fulfil our dreams, rather than magnify our fears and deepen our divisions.”

At the time of writing Amazon, Facebook, Google and Twitter had not responded to a request for comment.